We'd call this suspension hanging Delirious Hunter out to dry, but between the bondage and the corporal punishment she's dripping wet, even before the vibrators. The candle flame licking her ass and pussy is a huge turn on, too.
Flat on her back isn't a strenuous position but it has its own values. It lets Jack pull her nipples up with a pair of clamps and a pussy clamp is firmly in place. Flat on her stomach means we have the opportunity to work the other side of her. Her ass is perfect for caning while she's in a beautiful hogtie.